1. Field of the Invention
The present invention relates to devices for attaching to a ladder, and to ladders in combination with such devices. More specifically, the present invention relates to a wheeled attachment for a ladder, to allow the ladder to function as a hand truck.
2. Description of the Relevant Art
Service persons, such as electricians, plumbers, and heating and air conditioning mechanics, often work at sites remote from their shops or offices. Typically, tools and materials are transported to the work site using a service truck. Also, it is common that many jobs require the use of a stepladder.
Once the service truck is driven and parked close to the work site, the stepladder, tools and materials for the specific job must be carried from the service truck to the work site. When working in a location remote from the parking area, significant time is consumed carrying the stepladder, tools and materials to the work site. For example, one trip between an upper floor of a high rise building and a remote parking location can take more than half an hour. If several trips are required to bring the step ladder and all the necessary tools and materials to the work site, the total cost of the work is greatly increased. Therefore, the fewer trips required between the service truck and the work site, the more cost effectively the work can be performed.
One solution to carrying a stepladder, tools and materials between the service truck and the work site would be to use a hand truck. A hand truck offers a great conveyance, and eases the burden of the service person. However, if a service person were to use a hand truck, this would require that a hand truck be carried in the service truck. It is well known that space inside a service truck is limited, and often completely accounted for in accommodating the necessary stepladder, tools and materials.
To this end, a piece of equipment consolidating a stepladder and a hand truck has been proposed in the background art. U.S. Pat. No. 5,382,032, issued on Jan. 17, 1995 to James R. Wilson, and U.S. Pat. No. 3,954,155, issued on May 4, 1976 to Orlando Guidara, both illustrate a stepladder with wheels, which can function as a hand truck. Unfortunately, the devices of the background art suffer drawbacks.
Both references disclose fixed wheels, which protrude away from a top portion of the ladder. When a person uses the stepladder, the placement of the wheels encroaches on the user's upward movement. The encroachment forces the user to lean away from, rather than into the stepladder, especially as the user ascends higher on the ladder. Good safety practices recommend that a user should lean into, rather than away from, the ladder.
Another drawback is that the protruding, fixed wheels can be an obstacle to the user, and push against a user's body, when standing on the ladder and trying to reach to the sides of the ladder. If the wheels protrude above the top of the ladder, the wheels will interfere with placing and balancing a flat object, such as a board or a saw, on the flat top surface platform of the ladder.
Yet, another drawback is that the wheels are exposed in a prominent location at the top of the ladder, when the ladder is in use. If a user lost their balance, the user might grasp for the wheels to regain their balance. Since the wheels are rotatable, they would not lend themselves well for grasping in an emergency.
Another significant drawback is the positioning of the fixed wheels outside the limits of the side rails. In other words, the outer profile, or footprint, of the ladder is altered by the wheels when the ladder is folded up for storage. This arrangement requires additional space for storing the background art's device in a service truck. Further, the background art's device may not fit into a standard ladder rail, often provided on the top or side of a service truck.